Transfer of Fixation Using Affine Structure: Extending theAnalysis to Stereo

Abstract

This paper describes an algorithm for maintaining fixation upon a 3D body-centred point using 3D affine transfer, extending an earlier monocular method to stereo cameras. Transfer is based on corners detected in the image and matched over time and in stereo. The paper presents a method using all available matched data, providing immunity to noise and poor conditioning. The algorithm, implemented at video rates on a multi-processor machine, incorporates controlled degradation in the presence of insufficient data. Results are given from experiments using a four-axis active stereo camera platform, first which show the greater stability of the fixation point over the monocular method, both as it appears in the image and occurs in the scene; and, secondly, which show the recovery and evolution of 3D affine structure during fixation. It is shown that fixation and explicit structure recovery can occur separately, allowing the information required for gaze control to be computed in a fixed time.